kunomofo
Member
I may have to replace a couple pistons - not sure YET.
But my questions is this - there of course - are some NEW replacement pistons out there. When I was replacing them used on my Viper recently (one) I had suggested a new piston - but my mechanic said if we did that (or just replaced w a used piston and no cyclinder) we would have to have the cylinder bored out to match the piston.
So is that the case? If I buy a new piston (and if anyone has some suggestions on OEM or third party please let me know) do I need to have the cylinder bored to match?
Bottom line is I am looking for the best way to replace a blown piston - and head I suppose if needed. This has not been a fun winter...but at least there has not been tons of snow so I am not suffering too badly!
Thank you.
But my questions is this - there of course - are some NEW replacement pistons out there. When I was replacing them used on my Viper recently (one) I had suggested a new piston - but my mechanic said if we did that (or just replaced w a used piston and no cyclinder) we would have to have the cylinder bored out to match the piston.
So is that the case? If I buy a new piston (and if anyone has some suggestions on OEM or third party please let me know) do I need to have the cylinder bored to match?
Bottom line is I am looking for the best way to replace a blown piston - and head I suppose if needed. This has not been a fun winter...but at least there has not been tons of snow so I am not suffering too badly!
Thank you.
Those cylinders are nicasil so they cannot be bored. If going aftermarket, you need to replace all 3 so that the motor remains balanced. I would recommend spx pistons over weisco as weisco needs proper warm up all the time or it will seize a piston. Can we some pics of the damage when you open it up.
kunomofo
Member
ohhhhh OK - no clue to that. But replacing all three sounds good anyways.
Sure I will post some photos.
Sure I will post some photos.
TopGunnSrx
New member
Use OEM parts
Cooper0809
New member
I just blew my clutch side piston. Maim is right about the nicasil plating. You can take that cylinder back to the dealer and they'll take that from you and give you another one that's already been replated. And yes use oem pistons...
If the cylinder isn't damaged (plating isn't chipped or no gouges) replace the smoked piston with one that matches the other two (same brand). If your cylinder was cast iron I might agree with your tech, but it's not.
It's a good idea to check the bore and piston dimensions but I'd guess you'll find the bore is still within spec.
kunomofo
Member
So I am down two pistons and two cylinders.
So I just call a Yamaha dealer for the OEM parts? ugh I hate dealers - is that the best way to replace these?
heads are ok - yippeeee
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I think you need to check cylinders better, those might be still usable after cleaning.
kunomofo
Member
YES - agreed - we are doing that tomorrow. Looks like I can get a full set OEM pistons NEW - for about $229 - I will do all three.
Just waiting to see what the cylinders look like tomorrow when we pull them out.
kunomofo
Member
ok well - the cylinders look scored? But having never seen some bad ones or good ones I have nothing to go by really.
Do you think these need to be replaced?
Also - he said the powervalves were "stuck" ? Will they need to be fixed or replaced ? I have asked for photos of those too.
Of course after waiting a month - now we have tons of SNOW!!!! aahahhahahaaaaaa sux.
Do you think these need to be replaced?
Also - he said the powervalves were "stuck" ? Will they need to be fixed or replaced ? I have asked for photos of those too.
Of course after waiting a month - now we have tons of SNOW!!!! aahahhahahaaaaaa sux.
kunomofo
Member
I have three NEW OEM piston kits coming in that I ordered - I figured to replace all three even though only 2 are bad.
So now I have to deal with the two bad CYLINDERS.
So now I have to deal with the two bad CYLINDERS.
As long as the power valves are not pulled through, just clean them and reinstall. Scotch brite pad and some varsol work great. I use a surface dressing disc on a diegrinder.
Is that a chunk out of the cylinder above the port in the pic?
Is that a chunk out of the cylinder above the port in the pic?
kunomofo
Member
I dont know - is it? I was hoping to get some feedback here. I guess it looks like that yea...I see it now.
If there isnt any scratches you can feel and cylinder nicasil plating is not broken or cracked, it should be good with light honing. If you dont have honing machine, just take fine sandpaper and see how it works for scratches. I cant say from picture that are those bad or not. Just try light sanding so you see does those marks get away.
kunomofo
Member
What I was told is that there is a LOT of metal from the pistons on them. That cannot be sanded off - melted on metal.
I order THREE brand new OEM pistons - to replace them all - even tho one is fine. And I am ordering 2 cylinders used but in good condition.
So....I will have three new pistons in used cylinders - with all new rings, seals etc. Hoping to get the sled back up by next week - big snow coming this week and riding my "spare" sled (98 Cat ZR600) has been OK but not great! Looking forward to some increase in performance.
I order THREE brand new OEM pistons - to replace them all - even tho one is fine. And I am ordering 2 cylinders used but in good condition.
So....I will have three new pistons in used cylinders - with all new rings, seals etc. Hoping to get the sled back up by next week - big snow coming this week and riding my "spare" sled (98 Cat ZR600) has been OK but not great! Looking forward to some increase in performance.
Muriatic acid will desolve the aluminum and leave the chrome alone and should have been used before determining the condition of the cylinder... unless one wants to sell some cylinders.
kunomofo
Member
well thanks - we will try that first! was hoping for some feedback on the cylinders - thank you.
It may take some time if the deposits are heavy. Brush it on lightly keeping it out of the ports and off the aluminum casting. When it stops fizzing, rinse real well with water and check the condition of the walls paying close attention to the port openings for chipping and for obvious gouges.
kunomofo
Member
Thank you! I passed this along :-)
From one mofo to another ;>)